Genetic Variations among Different Variants of G1-like Avian Influenza H9N2 Viruses and Their Pathogenicity in Chickens

• Published in: Viruses Vol. 14; no. 5; p. 1030
• Main Authors: Adel, Amany, Abdelmagid, Marwa A, Mohamed, Ahmed Abd-Elhalem, Wasberg, Anishia, Mosaad, Zienab, Selim, Karim, Shaaban, Asmaa, Tarek, Mohamed, Hagag, Naglaa M, Lundkvist, Åke, Ellström, Patrik, Naguib, Mahmoud M
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 11-05-2022; MDPI
• Subjects: Analysis; Animals; antigenicity; Antigens; Avian flu; Avian influenza; Avian influenza viruses; Bronchitis; Care and treatment; Chickens; Control; Diagnosis; Diseases; Experimental infection; Experiments; Genetic aspects; genetic characterization; Genetic diversity; Genetic Variation; Genomes; Genotypes; Growth; Identification and classification; Infection control; Infections; Influenza A Virus, H9N2 Subtype - genetics; Influenza in Birds; Methods; Pathogenicity; Phylogenetics; Phylogeny; Poultry; reassortment; Risk factors; Software; Virulence; Viruses; Whole genome sequencing; Egypt; Middle East; Beijing China; United States > US; China; Germany; antigenicity; pathogenicity; reassortment; avian influenza; genetic characterization
• ISSN: 1999-4915; 1999-4915
• DOI: 10.3390/v14051030

Since it was first discovered, the low pathogenic avian influenza (LPAI) H9N2 subtype has established linages infecting the poultry population globally and has become one of the most prevalent influenza subtypes in domestic poultry. Several different variants and genotypes of LPAI H9N2 viruses have been reported in Egypt, but little is known about their pathogenicity and how they have evolved. In this study, four different Egyptian LPAI H9N2 viruses were genetically and antigenically characterized and compared to representative H9N2 viruses from G1 lineage. Furthermore, the pathogenicity of three genetically distinct Egyptian LPAI H9N2 viruses was assessed by experimental infection in chickens. Whole-genome sequencing revealed that the H9N2 virus of the Egy-2 G1-B lineage (pigeon-like) has become the dominant circulating H9N2 genotype in Egypt since 2016. Considerable variation in virus shedding at day 7 post-infections was detected in infected chickens, but no significant difference in pathogenicity was found between the infected groups. The rapid spread and emergence of new genotypes of the influenza viruses pinpoint the importance of continuous surveillance for the detection of novel reassortant viruses, as well as monitoring the viral evolution.